1. Field of the Invention
This invention relates to an air bubble hydromassaging apparatus comprising a blower housed in a control unit, a bubble grid adapted to be placed into a bathtub, and air tubing including a check valve to connect the control unit to the bubble grid, the control unit being provided with a bushing type compressed air outlet and the bubble grid being provided with a bushing type compressed air inlet. The air tubing has a connector fitting on each end by which it is detachably but airtightly connectible to the compressed air outlet of the control unit at one end and to the compressed air inlet of the bubble grid at the other end. A check valve is built into the connector fitting and serves to obstruct air passage through the connector fitting when the blower is in the OFF condition and opens to permit air passage through the connector fitting when the blower is in the ON condition.
2. Description of the Prior Art
An air bubble hydromassaging apparatus of this general type is known from German Pat. No. 30 44 880. The check valve enclosed in the connector fitting of the air tubing has the advantage that air bubble hydromassaging devices already in use may subsequently be fitted with a check valve of this particular type, simply by replacing the connector fitting of the air hose. In this prior check valve, the valve plunger is returned by a compression spring after the compressed air generator has been turned off. This frequent resetting may cause mechanical problems. Moreover, after some time, the compression spring, due to fatigue, is no longer able to forcibly hold the valve plunger in its closed position with sufficient closing power. Furthermore, the water flowing from the bubble grid back into the valve chamber has no way to drain from the valve chamber, but instead dams up and not only adversely affects the regulation of the valve plunger, but it may even pass into the control unit when the valve plunger is not closing properly. In addition, there is no assurance that the check valve operates properly because the connector fitting which encloses the check valve may also be inserted into the compressed air inlet of the bubble grid. In such case, the check valve is kept closed which may lead the compressed air to back up and thus place an undue load on the blower in operation.